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.\"     from: @(#)kgmon.8	8.1 (Berkeley) 6/6/93
.\"
.Dd $Mdocdate: March 12 2013 $
.Dt KGMON 8
.Os
.Sh NAME
.Nm kgmon
.Nd generate a dump of the operating system's profile buffers
.Sh SYNOPSIS
.Nm kgmon
.Op Fl bhpr
.Op Fl c Ar cpuid
.Op Fl M Ar core
.Op Fl N Ar system
.Sh DESCRIPTION
.Nm kgmon
is a tool used when profiling the operating system.
When no arguments are supplied,
.Nm kgmon
indicates the state of per-CPU operating system profilings as
.Dq running ,
.Dq off ,
or
.Dq not configured
(see
.Xr config 8 ) .
If the
.Fl p
flag is specified,
.Nm kgmon
extracts profile data from the operating system and produces a file for each
CPU suitable for later analysis by
.Xr gprof 1 .
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl b
Resume the collection of profile data.
.It Fl c Ar cpuid
Operate on the CPU specified by
.Pa cpuid ,
instead of all of them.
.It Fl h
Stop the collection of profile data.
.It Fl M Ar core
Extract values associated with the name list from the specified
.Ar core
instead of the default
.Pa /dev/kmem .
.It Fl N Ar system
Extract the name list from the specified
.Ar system
instead of the default
.Pa /bsd .
.It Fl p
Dump the contents of the profile buffers into a
.Pa gmon-<id>.out
file, where
.Dq id
is the ID of the CPU.
.It Fl r
Reset all the profile buffers.
If the
.Fl p
flag is also specified, the profile files are generated before the buffers are
reset.
.El
.Pp
If neither
.Fl b
nor
.Fl h
is specified, the state of profiling collection remains unchanged.
For example, if the
.Fl p
flag is specified and profile data is being collected,
profiling will be momentarily suspended,
the operating system profile buffers will be dumped,
and profiling will be immediately resumed.
.Sh FILES
.Bl -tag -width /dev/kmemx -compact
.It Pa /bsd
default system
.It Pa /dev/kmem
default memory
.El
.Sh DIAGNOSTICS
Users with only read permission on
.Pa /dev/kmem
cannot change the state
of profiling collection.
They can get profile files with the warning that the data may be inconsistent
if profiling is in progress.
.Sh SEE ALSO
.Xr gprof 1 ,
.Xr config 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.2 .
